Delta variant expected to become dominant strain in Virginia as case counts rise As the CDC announced the highly contagious Delta variant represented more than 80 percent of sequenced COVID cases in the country Tuesday, Virginia health experts predicted the Delta variant would soon become the dominant strain in the state as well. and last updated 2021-07-20 23:22:58-04 RICHMOND, Va. -- As the CDC announced the highly contagious Delta variant represented more than 80 percent of sequenced COVID cases in the country Tuesday, Virginia health experts predicted the Delta variant would soon become the dominant strain in the state as well.